Finding the Fourth Proportional to 78.76, 108.72 and 49.69

Step by Step Solution

1. Step 1: Write the proportion equation
   78.76 : 108.72 = 49.69 : x
2. Step 2: Convert to fraction form
   78.76/108.72 = 49.69/x
3. Step 3: Cross multiply
   78.76x = 108.72 × 49.69
4. Step 4: Simplify right side
   78.76x = 5,402.30
5. Step 5: Solve for x
   x = 5,402.30/78.76
6. Step 6: Final answer
   x = 68.59